I have a Mac and an Xbox 360. Is there a way to download mods on my computer, without downloading any software, and then put the mod onto a flash drive for my Xbox 360?
While there are ways to take your save from the Xbox 360 and edit it on your PC, (with something like Modio, for example) there are no ways to download mods for Skyrim on your PC and have them run on the Xbox 360.
No, unless you have Horizon or something. Microsoft is strict about mods.